LAMMPS (10 Feb 2021)
# Charge regulation lammps for simple weak electrolyte

units           real
atom_style      charge
neighbor        10.0 bin
read_data       data.chreg-acid-real
Reading data file ...
  orthogonal box = (-180.00000 -180.00000 -180.00000) to (180.00000 180.00000 180.00000)
  1 by 2 by 2 MPI processor grid
  reading atoms ...
  219 atoms
  read_data CPU = 0.002 seconds

#real units
variable 	sigma equal 7.2	              # particle diameter 0.72 nm
variable	temperature equal 298         # temperature 298 K
variable        kb index 0.0019872067         # kB in Kcal/mol/K
variable 	epsilon equal ${kb}*${temperature}
variable 	epsilon equal 0.0019872067*${temperature}
variable 	epsilon equal 0.0019872067*298
variable	tunit   equal 	2000          # time unit is 2000 fs
variable	timestep equal 0.005*${tunit}
variable	timestep equal 0.005*2000

variable        cut_long equal 12.5*${sigma}
variable        cut_long equal 12.5*7.2
variable        nevery equal 100
variable        nmc equal 100
variable        pH equal 7.0
variable        pKa equal 6.0
variable        pIm equal 3.0
variable        pIp equal 3.0

variable        cut_lj equal 2^(1.0/6.0)*${sigma}
variable        cut_lj equal 2^(1.0/6.0)*7.2
velocity        all create ${temperature} 8008 loop geom
velocity        all create 298 8008 loop geom

pair_style      lj/cut/coul/long ${cut_lj} ${cut_long}
pair_style      lj/cut/coul/long 8.08172674782749 ${cut_long}
pair_style      lj/cut/coul/long 8.08172674782749 90
pair_coeff      * *  ${epsilon} ${sigma}
pair_coeff      * *  0.5921875966 ${sigma}
pair_coeff      * *  0.5921875966 7.2
kspace_style    pppm 1.0e-3
dielectric	78
pair_modify     shift yes

#########  VERLET INTEGRATION WITH LANGEVIN THERMOSTAT  ###########
fix             fnve all nve
compute         dtemp all temp
compute_modify  dtemp dynamic yes
fix             fT all langevin $(v_temperature) $(v_temperature) $(v_tunit) 123
fix             fT all langevin 298 $(v_temperature) $(v_tunit) 123
fix             fT all langevin 298 298 $(v_tunit) 123
fix             fT all langevin 298 298 2000 123
fix_modify      fT temp dtemp

fix chareg      all charge/regulation 2 3 acid_type 1 pH ${pH} pKa ${pKa} pIp ${pIp} pIm ${pIm} lunit_nm 0.1 nevery ${nevery} nmc ${nmc} seed 2345 tempfixid fT
fix chareg      all charge/regulation 2 3 acid_type 1 pH 7 pKa ${pKa} pIp ${pIp} pIm ${pIm} lunit_nm 0.1 nevery ${nevery} nmc ${nmc} seed 2345 tempfixid fT
fix chareg      all charge/regulation 2 3 acid_type 1 pH 7 pKa 6 pIp ${pIp} pIm ${pIm} lunit_nm 0.1 nevery ${nevery} nmc ${nmc} seed 2345 tempfixid fT
fix chareg      all charge/regulation 2 3 acid_type 1 pH 7 pKa 6 pIp 3 pIm ${pIm} lunit_nm 0.1 nevery ${nevery} nmc ${nmc} seed 2345 tempfixid fT
fix chareg      all charge/regulation 2 3 acid_type 1 pH 7 pKa 6 pIp 3 pIm 3 lunit_nm 0.1 nevery ${nevery} nmc ${nmc} seed 2345 tempfixid fT
fix chareg      all charge/regulation 2 3 acid_type 1 pH 7 pKa 6 pIp 3 pIm 3 lunit_nm 0.1 nevery 100 nmc ${nmc} seed 2345 tempfixid fT
fix chareg      all charge/regulation 2 3 acid_type 1 pH 7 pKa 6 pIp 3 pIm 3 lunit_nm 0.1 nevery 100 nmc 100 seed 2345 tempfixid fT
thermo          100
thermo_style custom step pe c_dtemp f_chareg[1] f_chareg[2] f_chareg[3] f_chareg[4] f_chareg[5] f_chareg[6] f_chareg[7] f_chareg[8]
timestep        ${timestep}
timestep        10
run             2000
PPPM initialization ...
  using 12-bit tables for long-range coulomb (../kspace.cpp:339)
  G vector (1/distance) = 0.019408615
  grid = 8 8 8
  stencil order = 5
  estimated absolute RMS force accuracy = 0.00012527706
  estimated relative force accuracy = 3.7726815e-07
  using double precision KISS FFT
  3d grid and FFT values/proc = 1053 128
0 atoms in group FixChargeRegulation:exclusion_group:chareg
WARNING: Neighbor exclusions used with KSpace solver may give inconsistent Coulombic energies (../neighbor.cpp:486)
Neighbor list info ...
  update every 1 steps, delay 10 steps, check yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 100
  ghost atom cutoff = 100
  binsize = 50, bins = 8 8 8
  1 neighbor lists, perpetual/occasional/extra = 1 0 0
  (1) pair lj/cut/coul/long, perpetual
      attributes: half, newton on
      pair build: half/bin/atomonly/newton
      stencil: half/bin/3d/newton
      bin: standard
Per MPI rank memory allocation (min/avg/max) = 3.624 | 3.624 | 3.624 Mbytes
Step PotEng c_dtemp f_chareg[1] f_chareg[2] f_chareg[3] f_chareg[4] f_chareg[5] f_chareg[6] f_chareg[7] f_chareg[8] 
       0   -6.4798431          298            0            0            1           99            0            0          109           10 
     100   -7.6327126    304.68909          100           73           15           85            0            0           94            9 
     200   -6.1699041    272.19597          200          156           24           76            0            0           87           11 
     300   -7.7876571    288.90801          300          240           20           80            0            0           87            7 
     400   -6.3239918    274.65708          400          315           16           84            0            0           90            6 
     500   -5.3978659    257.49208          500          398           15           85            0            0           93            8 
     600   -5.6433949    322.52048          600          477           18           82            0            0           90            8 
     700   -6.5351367    269.20244          700          558           18           82            0            0           91            9 
     800   -6.2093085    315.21326          800          638           24           76            0            0           83            7 
     900   -7.0795998    311.93228          900          719           28           72            0            0           82           10 
    1000   -6.4668438    281.72674         1000          796           27           73            0            0           81            8 
    1100   -6.2377994    318.48594         1100          875           25           75            0            0           84            9 
    1200   -6.6305072     304.9091         1200          950           23           77            0            0           87           10 
    1300   -5.9624552    286.05027         1300         1029           22           78            0            0           86            8 
    1400   -4.4695814    261.81053         1400         1111           20           80            0            0           90           10 
    1500   -5.6928652    293.72403         1500         1191           24           76            0            0           86           10 
    1600   -6.8715413    290.47065         1600         1275           22           78            0            0           90           12 
    1700   -6.5067505    292.74735         1700         1356           25           75            0            0           85           10 
    1800   -5.3902702    307.79012         1800         1434           22           78            0            0           83            5 
    1900   -5.1407153    318.48918         1900         1510           21           79            0            0           87            8 
    2000   -4.9514719    281.87771         2000         1589           25           75            0            0           82            7 
Loop time of 0.562889 on 4 procs for 2000 steps with 189 atoms

Performance: 3069.876 ns/day, 0.008 hours/ns, 3553.097 timesteps/s
99.6% CPU use with 4 MPI tasks x no OpenMP threads

MPI task timing breakdown:
Section |  min time  |  avg time  |  max time  |%varavg| %total
---------------------------------------------------------------
Pair    | 0.008399   | 0.010383   | 0.011765   |   1.2 |  1.84
Kspace  | 0.17501    | 0.17543    | 0.1757     |   0.1 | 31.17
Neigh   | 0.001833   | 0.0021325  | 0.002293   |   0.4 |  0.38
Comm    | 0.023099   | 0.024255   | 0.026645   |   0.9 |  4.31
Output  | 0.000465   | 0.000546   | 0.000783   |   0.0 |  0.10
Modify  | 0.3464     | 0.34669    | 0.34698    |   0.0 | 61.59
Other   |            | 0.003452   |            |       |  0.61

Nlocal:        47.2500 ave          57 max          41 min
Histogram: 1 1 0 1 0 0 0 0 0 1
Nghost:        285.750 ave         303 max         263 min
Histogram: 1 0 0 0 1 0 0 0 1 1
Neighs:        403.500 ave         548 max         324 min
Histogram: 2 0 0 1 0 0 0 0 0 1

Total # of neighbors = 1614
Ave neighs/atom = 8.5396825
Neighbor list builds = 2081
Dangerous builds = 0
Total wall time: 0:00:00
